Burner



Patented Mar. 17, 1942 UNITED TES PATENT OFFICE BURNER Application February 18, 1941, Serial No. 379,&21

10 Claims.

This invention relates to fuel burners and more particularly to rotary fuel burners of the reaction type wherein fuel issuing from a reaction rotor drives the air fan.

The invention is particularly applicable to industrial gas or oil burners, although it may be applied to various burners which are adapted to use a fuel capable of furnishing the necessary reaction forces for driving the rotor.

An object of the invention is to provide a novel and improved burner of the above type in which the fuel is prevented from passing through the rotor bearings.

Another object is to provide'a burner of the above type in which the bearings are cooled by the fuel supplied to the burner.

Another object is to provide a burner of the above type having novel and improved combinations of parts and details of Construction.

Various other objects and advantages will become apparent as the nature of the invention is more ully disclosed.

Although the novel features which are believed to be characteristic of this invention are pointed out more particularly in the claims appended hereto, the invention itself may be better understood by referring to the following description, taken in connection with the accompanying drawing, in which a specific embodiment thereof has been set forth for purposes of illustraticn.

In the drawing,

Fig. 1 is a longitudinal section through a burner embodying the present invention;

Fig. 2 is a partial transverse section taken on the line 2-2 of Fig. 1; and

Fig. 3 is a partial longitudinal section similar to Fig. 1 illustrating a further embodiment of the invention.

Reerring to the drawing more in detail, the inventicn is shown as applied to a burner associated with a burner opening lil in a furnace wall I I. The burner comprises a tubular shell [2 positioned within the burner opening &B and forming a longitudinal channel through which the air for combustion passes. A spider M is adjustably Secured in the shell !2 by means of set screws !5. The spider 14 is provided with a hollow hub member !5 having an inner wall ll forming a central hearing chamber !3 closed at one end, and an outer wall ai! spaced from the wall I'l to provide an annular fuel passage ZI. The inner and outer walls may be Secured together by ribs 22 which are shown as arranged in alignment with arms 23 of the spider M. A fuel supply pipe 25 is Secured to the outer wall 213 a of the hub i@ to supply fuel to the annular fuel passage 2l. In the embodiment shown the fuel pipe extends rearwardly from the hub 16 at the closed end of the bearing chamber coaxially with the hub and with the shell [2. The pipe 25` is shown as held by a thumb screw 27 in a bracket 25 which is Secured in the shell [2 by suitable means not shown.

A hollow shaft 30 is mounted for rotation in anti-friction bearings :H and 32 within the bearing chamber s, shown as ball bearings. The shaft 39 projects forwardly beyond the hub |6 and carries, at its forward (furnace) end, a reaction rotor 34 and a fan 35. The fan 35 is provided with a hollow hub 31 which is secured to the shaft 3@ by means of a set screw 38. The reaction rotor 35 comprises reaction arms 36 Secured in a cap m, which is threaded over the open end of the shaft 353 and held by a set screw AI'. The arms 35 are provided with a plurality of-apertures 42 which are spaced radially for the purpose to be described. The inner or rear send of the shaft 35 is closed by a cap 43.

The inner ball race 3Ia of the hearing 3! is seated against a shoulder 45 on the shaft 30. A spacing member 46 extends between the inner ball race tia of the bearinga and the inner ball race 32a of the bearing 32. A shield or oil fiinger al' is shown as mounted on the shaft 30 adjacent the hearing 32. A spacing member 48 extends from the fiinger 41 to the hub 31 of the fan 35. All of the parts above mentioned are accordingly clamped in axial position by the threaded hub 40 of the reaction rotor.

The outer ball race 321) of the hearing 32 is held in position between a shoulder 59 formed in the wall and a follower 52 which is Secured over the end of the wall Il' by screws 53 and is provided with a flange 54 which forms a cover substantially clcsing the hearing chamber !8.

A cover 55 is attached to the outer Wall 24) of the hub i& by bolts 56. This cover Eh is spaced from the fiange M to provide a continuation Ela of the annular fuel passage 28 and is sealed by suitable means, shown as a labyrinth packing 57, to the spacing member %8 on shaft 363. A plu rality of apertures 58 are formed in the shaft 39 and in the spacing member 4 8 in registration with the continuation 2%& of the annular fuel passage 2 I'.

suitable oil means shown as an oil supply hole 58 and an oil drain pipe fil may be provided for oiling the bearngs 3! and 32.

The flow of combustion air through the passage within the shell !2 may be controlled by a shield 65 having a hub 66 which is mounted on the pipe 25 and adjustably held in position by a set screw 61. The shield 65 may be provided with a sight and ignition opening 68 having a cover 69 pivotally Secured thereto by a bolt 70.

operation In the operation of this device, the fuel, which may comprise gas or oil or other fluid fuel, is fed by the stationary pipe 25 to the annular fuel space 2! within the hub [6 from which it passes through the apertures 58 into the interior of the hollow shaft 30, to the hollow cap 40, the reaction arms 36 and the apertures 42. The reaction of the fuel issuing from the apertures 42 causes the rotor, including the arms 36, shaft 30 and fan 35 to rotate. The apertures 42 are so positioned as to produce a substantially uniform distribution of fuel across the entire cross-seotional area of the burner. The fan 35 produces through the shell !2 a flow of air for combustion which is thoroughly mixed with the uel issuing from the apertures 42 to form a combustible mixture. The bearings are cooled by the flow of uel through the passage 2! and by the flow of air over the hub !6.

The closed rear end of the shaft 38 prevents the escape of fuel into the hearing chamber 18. Inasmuch as the bearing chamber !8 is closed at one end fuel is thus prevented from passing therethrough.

It is to be noted that the burner may be shifted axially by adjusting the position of the spider !4 in the shell !2. The shield 65 may also be shifted axially independently in accordance with the air flow desired.

The' fan 35 may be provided With any desired number of blades depending upon the air flow characteristics and the reaction rotor 34 may be provided with a plurality of arms 36 which may or may not be the same in number as the number of blades of the fan 35, depending upon the characteristics of the fuel being burned. The driving (reaction) arms may be removed and replaced without disturbing the fan and may be adjusted to any desired angular relationship with respect to the fan blades.

By positively eliminating the flow of fue] through the hearing chamb er, the life of the bearings is materially increased. This is acconplished in the embodiment shown in a simple and eicient-manner. The burner is sturdy and dependable and is well suited to commercial use.

The embodiment of Fig. 3 operates sirnilarly to the embodiment of Figs. 1 and 2. The construction however, has been altered to permit the use of a solid shaft or spindle instead of the hollow shaft 30 of Fig. 2. Referring to Fig. 3, parts similar to Figs. 1 and 2 have been given the same reference characters and Will not be redescribed. In this embodiment the hollow shaft 30 is replaced by a solid shaft 80, which is mounted to rotate in the bearings 3! and 32. The shat 80 is provided with a shoulder 81' against which the inner ball race 3|a of the hearing 31 is seated. The fan S is shown as provided with a hollow hub 82 which is mounted on a hollow sleeve 83. The sleeve 83 is provided with a pair of hub members 84 and 35 which are mounted on the shaft 80. The hub member M bears against the flinger 41 for clamping the parts in position. The sleeve 83 is provided with an upturned fiange 85 having a running fit within the outer wall 28 of the hub !5 to which it is sealed by a labyrinth packing 8?.

The cap 40 is formed with a skirt 90 which eX- tends over the sleeve 83 and engages a shoulder 91 ormed in the hub 82 of the fan 35. The skirt 90 may be Secured to the hub 82 by means of a set screw 92 In this embodiment the cap 40 may be keyed on the shaft and Secured by a nut 83. The nut 93`c1amps the skirt 99 of the cap 40 against the hub 82 of the fan 35. This, in turn, is clamped against the upturned flange 83 of the sleeve 83, the hub 84 of which is caused to engage the flinger 41. The fiinger 41 bears against the inner ball race 32a of the hearing 32 from which the clamping force is exerted through the spacing member 46 and the inner ball race 3la of the bearing 3! against the shoulder 8! of the rotating shait 80. The flange 85 is shown as Contacting the hub 82 of the fan 35 on an inclined line 83 which extends at an angle so related to the relative coefficients of expension of the various parts that it is suited to compensate for any inequalities in rate of expansion so that the hub 82 may be tightly clamped against the sleeve 83 by means of the cap 40 as above described. The hub 82 may, however, be Secured to the sleeve 83 by other means, such as a set screw, if desired.

In the Construction shown in Fig. 3, the fuel from the pipe 25 passes through the annular uel passage 2| sleeve 83, which communicates through the cap 40 with the arms 36. Inasmuch as there is no passage for the fuel through the hearing chamber, there is no tendency for fuel to flow therethrough. The solid shaft in this embodiment permits the use of comparatively small diameter bearings and thus reduces the weight of the rotating parts.

Both of these embodiments are characterized by the provision of a hearing chamber which is permanently closed at one end so as to prevent any through passage of fuel. The passage 2| may extend substantially around the hearing chamber for cooling purposes or may be limited to the closed end of the hub if the cooling effect is not required in any particular installation. The burner may be used with gaseous fuel or with liquid fuel, such as oil, or oil which has been atomized by steam or other agents.

Although a specific embodiment has been shown for purposes of illustration, it .is to be understood that various changes and modifications may be made therein and that the invention is only to be limited in accordance with the scope of the following claims.

What is claimed is:

1. A burner comprising a stationary supporting hub having a central hearing chamber, a shaft rotatably mounted in said hearing chamber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures, forming reaction jets, a fuel passage rotating with said hollow hub member and communicating therewith to supply fuel to said rotor for driving the same, and a stationary uel supply conduit communicating with said rotating fuel passage at a point between said hearing chamber and said reaction rotor, said conduit being constructed and arranged to avoid flow of fuel through said hearing chamber.

and thence to the interior of the 2. A burner comprising a stationary supporting hub having a central bearing chamber closed at one end, a shaft rotatably mounted in and projecting from the open end of said bearing Cham ber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures orming reaction jets, a fuel passage rotating with said hollow hub member and communicating therewith to supply fuel to said rotor for driving the same, and a stationary fuel supply conduit communicating with said rotating fuel passage at a point between said bearing chamber and said reaction rotor, said conduit being constructed and arranged to avoid flow of uel through said bearing chamber.

3. A burner comprising a stationary supporting hub having a central bearing chamber, a shaft rotatably mounted in said bearing chamber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for combustion mounted on said shaft to drive a said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures -forming reaction jets, a fuel passage rotating with said hollow hub member and communicating therewith to supply fuel to said. rotor for driving the same, and a stationary fuel supply passage substantially surrounding said bearing chamber and communicating with said rotating uel passage at a point between said bearing chamber and said reaction rotor, Whereby the fuel fiowing through said stationary passage serves to cool said bearing chamber, said stationary passage being constructed and arranged to avoid flow of fuel through said bearing chamber.

4. A burner comprising -a stationary supporting hub having a central bearing chamber having a closed end, a shaft rotatably mounted in and projecting from the open end of said bearing chamber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures orming reaction jets, a fuel passage rotating with said hollow hub member and communicating therewith to supply fue] to said rotor for driving the same, and a stationary fuel supply passage substantially surrounding said bearing chamber and communicating with said rotating fuel passage at a point between said bearing chamber and said reaction rotor, whereby the fuel fiowing through said stationary passage serves to cool said bearing chamber, said stationary passage being 'constructed and arranged to avoid flow of fuel through said bearing chamber.

5. A burner comprising a tationary supporting hub having a central bearing chamber closed at one end and having fuel passage substantially surrounding said bearing chamber, spa-ced antifriction bearings in said chamber, a shaft rotatably mounted in said bearings and projecting from the open end of said chamber, an air fan and a reaction rotor driven by the fuel for combustion mounted on said shaft, a 'fuel supply pipe co-axial with said hub supplying fuel to said passage at the closed end. of said chamber, means supplying fuel from said fuel passage after owing around said bearing chamber to said reaction rotor whereby the fuel flowing through said uel passage serves to cool said bearing chamber, means at the open end of said bearing chamber forming a fluid seal with said shaft, and an oil fiinger on said shaft :between said last means and said bearings.

6. A burner according to claim 1 in which the shaft is hollow and provides the rotating passage to supply fuel to said reaction rotor, said shaft having apertures to receive fuel from said fuel supply conduit.

7. A burner according to claim 2 in which the shaft is hollow and provides the rotating passage to supply fuel to said reaction rotor, said shaft i having apertures to receive fuel from said fuel` tion with said fuel supply means :and with said reaction rotor to supply fuel from said fuel sup ply means to said rotor.

9 In a burner according to claim 1, a hollow sleeve mounted on said shaft to provide the rotating passage, said sleeve being in'communication with said fuel supply means and With said reaction rotor to supply fuel from said fuel supply means to said rotor, said -fan having a hollow hub and being mounted on said sleeve.

10. In a burner according' tool-aim 1, a hollow sleeve mounted on saidshaft, said sleeve being in communication with said fuel supply means and with said reaction rotor to supply fuel from said fuel supply conduit to said rotor, said fan having a hollow hub and being mounted on said sleeve, and means clamping said reaction rotor, fan and sleeve on said shaft for rotation in unison. v

DAVID P. GRAHAM. 

